Research on input and output connections and amplitude control of saccadic eye movement by multiple electrode recording.

为了分析具有二维视网膜定位图的上级丘的空间和时间活动，研制了一套多通道神经元单位活动数字信号同步连续记录系统。该系统由手工制作的数字集成电路和计算机组成，具有通道数不限、可连续长时间记录或触发间歇重复记录等优点。在速度方面，连续记录模式下，5 kHz采样可达256个通道，直至计算机硬盘满。为了分析上级丘视网膜定位图中不同区域的传入和传出纤维联系，建立了生物素葡聚糖胺标记的单轴突三维重建方法。在此之前，我尝试建立了大鼠小脑的实验方法。我发现，单一的轴突起源于下橄榄核和外侧网状核经常支配小脑核。阐明了这些单轴突在小脑皮质和小脑核中的分支和神经支配模式。在延髓头端的旁正中网状结构中发现了一条新的传入神经轴突，它选择性地投射到小脑核，但几乎不投射到小脑皮质。在小脑实验中，改进了明胶包埋、组织化学处理和组织反应室的制作方法，建立了实验方案。关于上级丘的联系，我们发现内侧副橄榄尾侧部的腹内侧部接受来自上级丘的传入，然后投射到大鼠小脑蚓部的第VI小叶和第VII小叶。

A simultaneous and continuous recording system of multi-channel digital signals of neural unitary activities was developed in order to analyze spatial and temporal activity of the superior colliculus that has two-dimensional retinotopical map. The system is composed of hand-made circuits of digital ICs and a computer and has advantages such as limitless channel number, and continuous long-time recording or triggered intermittent repetitive recording. Concerning the speed, 5 kHz sampling can be done with 256 channels in the continuous recording mode until the computere hard disk becomes full.A method of three-dimensional reconstruction of single axons by tracing with biotinylated dextran amine labeling was developed in order to analyze afferent and efferent connections in different areas in the retinotopical map in the superior colliculus. In advance, I tried to establish the methods in experiments in the rat cerebellum. I found that single axons originating from the inferior olivary nucleus and the lateral reticular nucleus frequently innervate the cerebellar nucleus. Branchings and innervation patterns of these single axons in the cerebellar cortex and cerebellar nucleus were clarified. A new afferent axons selective to the cerebellar nucleus that barely projected to the cerebellar cortex was found. These axons originated from the paramedian reticular formation in the rostral medulla. During the experiments in the cerebellum, methods for gelatin embedding and histochemical treatment and fabrication of tissue reaction chamber were improved and experimental protocol was established. Concerning superior collicular connections, it is was found that the ventromedial portion of the caudal part of the medial accessory olive, which was shown to receive afferent from the superior colliculus, then projected to lobule VI and VII in the rat cerebellar vermis.